Balansering av förmonteringsline för lastbilshytter vid Scania i Södertälje
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Scania is facing big challenges in the future. The constantly increasing competition requires Scania to constantly improve its production system. At the Chassis assembly in Södertälje, final assembly of trucks is performed. This master’s thesis has been carried out at one section of the Chassis assembly where cabs are being prepared for mounting on the truck chassis. In this section, the Cab pre-assembly, there are many opportunities for improvement.The function of the Cab pre-assembly is to mount air deflectors, front hatch and sunvisor on the cab. The Cab pre-assembly is divided into a number of workstations where different tasks are performed. At the air deflector station the air deflectors are mounted on the cab. At station 1 front hatches are preassembled, and subsequently mounted on the cab at the front hatch station. At the sunvisor station sunvisors are preassembled and then mounted on the cab. There are a variety of cab types, air deflector types, front hatch types and sunvisor types. This makes it difficult to level out, or balance, the workload on the different stations.The master’s thesis was initiated with a comprehensive data-gathering phase. Observation, interviews and time studies were performed to create insight in the situation on the Cab pre-assembly. The result of the time study was an extensive amount of data, which includes operation times for all tasks, for different types of cabs.The time studies showed that many of the cab types on the air deflector and front hatch stations takes more time than the takt time. This forces the assemblers to work really hard, but still they cannot always keep up. On other cab types the assembler at the air deflector station has no work at all. At station 1, on the other hand, all types of front hatches take shorter time than the takt time. For the assembler at the sunvisor station, all different types of sunvisors take different amount of time to assemble and mount, but the work can always be done within takt time.At the Cab pre-assembly there is also an assembler, known as a variant, who performs certain tasks at some types of cabs that takes more than the takt time to assemble. For example, this variant helps the assembler at the air deflector station with one type of cab that otherwise could not be assembled within takt time. The variant has many different tasks, and frequently a number of these tasks should be performed at the same time. Because of this the variant cannot carry out all tasks, and the assemblers who should have gotten help cannot perform their tasks in time.To even out the workload in the Cab pre-assembly and to unburden the variant, a concept for balancing of the Cab pre-assembly was developed. This concept includes- merging the front hatch station with the sunvisor station and letting a single assembler handle the workload at this new station- letting a variant preassemble the sunvisors that take long time to assemble and mount, to enable the above- moving some of the work, previously performed at the front hatch station, to station 1 and some of it to the air deflector station- moving the assembler from the front hatch station to the air deflector station and dividing the work at this station between the assembler at the air deflector station and this new assembler- unburden the variant of many tasks that the assemblers at the air deflector station can perform when they have no other work to do.Moving work from the front hatch station to the air deflector station was a prerequisite for implementing this solution. Therefore this concept was tried out in real production. This trial showed that it was possible for the assemblers to do their work within the takt time, but that it resulted in some ergonomic problems. By changing the sequence the work tasks were performed in, these problems could be solved. Evaluation indicates that the concept for balancing the Cab pre-assembly is feasible and that the concept would considerably improve the situation at the Cab pre-assembly.Scania is recommended to implement this concept at the Cab pre-assembly, to be able to solve many of the problems that exist in this section of the Chassis assembly.
Place, publisher, year, edition, pages
2012. , 144 p.
Teknik, Balansering, montering
IdentifiersURN: urn:nbn:se:ltu:diva-46454Local ID: 417c4cb9-8abd-4a24-ac36-06888b29cd8eOAI: oai:DiVA.org:ltu-46454DiVA: diva2:1019768
Subject / course
Student thesis, at least 30 credits
Industrial Design Engineering, master's level
Validerat; 20120628 (anonymous)2016-10-042016-10-04Bibliographically approved